/jest-runtime

Custom runtime for Jest which addresses memory issue

Primary LanguageJavaScriptMIT LicenseMIT

@side/jest-runtime

Custom runtime for Jest which addresses memory leak when using Typescript

Build Status Coverage semantic-release Code Style

NOTE This package was intentionally left as JS instead of being converted to TS because it is only a slight modification of existing Jest code based on this PR

  1. Install SWC if you haven't already @swc/core @swc/jest

  2. Make sure to configure SWC if you haven't already:

    {
       "jsc": {
          "parser": {
             "syntax": "typescript",
             "decorators": true
          },
          "transform": {
             "legacyDecorator": true,
             "decoratorMetadata": true
          }
       }
    }
    
  3. Install custom runtime: yarn add @side/jest-runtime

  4. Use within jest.config.js:

    module.exports = {
      transform: {
        '^.+\\.ts$': '@swc/jest',
      },
      runtime: '@side/jest-runtime',
    };

Why?

We were seeing memory leaks using ts-jest with node >16.10. When investigating solutions this PR fixing the issue was noticed. Since it hasn't been merged, and we still wanted to share this logic, we created this lib.